- 期刊
IRMA校正濃度範圍內之Hook Effect
Hook Effect of IRMA within the Range of Calibrators
摘要
Background: High-dose hook effect is a phenomenon associated with an immunometric assay. It may give falsely low results for several tumor markers, such as CA125, CA199, prolactin, etc. The aim of this study was to investigate if falsely low value report appears in alpha-fetoprotein and CA125 analyses within the range of calibrators. Methods: From March 2008 to January 2009, the samples of immunoradiometric assay (IRMA) for AFP with data of 500-780 ng/ml and for CA125 with data of 350-500 U/ml were collected. The samples were subject to 1:10 dilution or more with assay kit dilution buffer prior to analysis. The data of diluted samples were compared with undiluted ones. Results: Sixty-one AFP and 34 CA125 samples were rechecked. After dilution, 3 AFP data were 5 times higher than the original data, and 1 specimen was 4.88 times higher. Three CA125 data were ≥3.38 times than the original data. There were 39.3% and 35.3% of diluted AFP and CA125 specimen, respectively, with coefficient of variation (CV) ≥15%. Among the data groups before dilution (AFP: 500-599.9 ng/ml, 600-699.9 ng/ml and 700-780 ng/ml; CA125: 350-399.9 U/ml, 400-449.9 U/ml and 450-500 U/ml), we statistically rechecked the ones showing CV ≥15%, and an insignificant difference (P ＞0.05) was observed. Conclusion: Hook effect was founded in some reports of immunometric assay. There was no solid evidence in selected data range to identify which concentration may induce hook effect. Nevertheless, we should carefully recheck the high concentration data in order to reduce the incidence of hook effect.
並列摘要
Background: High-dose hook effect is a phenomenon associated with an immunometric assay. It may give falsely low results for several tumor markers, such as CA125, CA199, prolactin, etc. The aim of this study was to investigate if falsely low value report appears in alpha-fetoprotein and CA125 analyses within the range of calibrators. Methods: From March 2008 to January 2009, the samples of immunoradiometric assay (IRMA) for AFP with data of 500-780 ng/ml and for CA125 with data of 350-500 U/ml were collected. The samples were subject to 1:10 dilution or more with assay kit dilution buffer prior to analysis. The data of diluted samples were compared with undiluted ones. Results: Sixty-one AFP and 34 CA125 samples were rechecked. After dilution, 3 AFP data were 5 times higher than the original data, and 1 specimen was 4.88 times higher. Three CA125 data were ≥3.38 times than the original data. There were 39.3% and 35.3% of diluted AFP and CA125 specimen, respectively, with coefficient of variation (CV) ≥15%. Among the data groups before dilution (AFP: 500-599.9 ng/ml, 600-699.9 ng/ml and 700-780 ng/ml; CA125: 350-399.9 U/ml, 400-449.9 U/ml and 450-500 U/ml), we statistically rechecked the ones showing CV ≥15%, and an insignificant difference (P ＞0.05) was observed. Conclusion: Hook effect was founded in some reports of immunometric assay. There was no solid evidence in selected data range to identify which concentration may induce hook effect. Nevertheless, we should carefully recheck the high concentration data in order to reduce the incidence of hook effect.